2006/04/19 by Yasumasa Hasegawa, Rikio Konno, Hiroki Nakano +1 · 6 citations
Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum, superfluid, helium dynamics #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.74.033413
published as Phys. Rev. B 74, 033413 (2006) · 4 pages, 6 figures
arxiv created 2006/04/19 · openalex publication_date 2006/07/28 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Tight-binding electrons on the honeycomb lattice are studied where nearest-neighbor hoppings in the three directions are ta, tb, and tc, respectively. For the isotropic case---namely, for ta=tb=tc---two zero modes exist where the energy dispersions at the vanishing points are linear in momentum k. Positions of zero modes move in the momentum space as ta, tb, and tc are varied. It is shown that zero modes exist if \ensuremath|\ensuremath|\fractbta\ensuremath|\ensuremath-1\ensuremath|\ensuremath\leqslant\ensuremath|\fractcta\ensuremath|\ensuremath\leqslant\ensuremath|\ensuremath|\fractbta\ensuremath|+1\ensuremath|. The density of states near a zero mode is proportional to \ensuremath|E\ensuremath| but it is propotional to √\ensuremath|E\ensuremath| at the boundary of this condition